Process of producing isoprene.



1,070,120.v 1T0 Drawing.

UNITED smras PATENT OFFICE.

RICHARD BLAIR EABLE AND LUGAS PETBON KYRIAKIDES, OF BOSTPNflQTASSLGH U-SE'ITS, ASSIGIIOBfi'l-O HOOD RUBBER COMPANY, OF BOSTON, MASSAQUSETTS, A

CORPORATION OF. MASSACHUSETTS,

PBOCMS OF PRODUCING I SOPRENE.

Specification of Letters Patent. Application flled flovenrh er 1:1,19!1.' Serial No. 659,826.

" PatentedAug.12,191 3.x

To all :inkcm it may) concern:

Be 1t own that we, RICHARD B. EARLE and LUCAS P. KYniAigmns, citizensofthe United States, residing at Boston, Massamillimeters of mercury.

In order to illustrate the new process more fully the following exampleis given Amylene oxid is .distilled slowly over alumi- -=num silicate,either powdered or in briquet form, which is kept at a temperature of450;?

(1., and a pressure of one millimeter of-mercury by a vacuum pump. Theproducts of the reaction are condensed in suitable receivers by "meansof refrigerating agents, and purified by fractional distillation.

The fraction boiling from 32 a: "o.

consists of nearly pure lsoprene and may be used in this form. The otherproducts of the reaction arehigh boiling products of unknown nature,methylisopropyl ketone and traces of trimethylethylene.

The yield of isoprene, containing only traces of 'trimethylethylene, isover 70% of the theory.

The formation of isoprene takes place by the splitting-01f ofwateraccording to'the equation: v

The process is useful at the ordinary pres WWO.

valuproducts.

We claim; v 1. A- process. for producing isoprene, which comprisespassing the vapors of isoamylene oxid of the formula e o cni-d-bn-cm' A,H, over a heated dehydrating catalytic.agent and separating the isopreneformed from the other products.

2. A process for producing isoprene, which comprises passing the vaporsof isoamylene oxid of the formula 0 CHgwQH-CH over a dehydratingcatalytic agent heated to a temperature between 400 and 600 0. andseparating the isoprene formed from the other products. y

3. A process for producing isoprene, which comprises passing the vaporsof isoamylene oxid of the formula o CHg-(EH-CH;

' CH; 7 over a heated dehydrating catalytic'agent at less thanatmospheric pressure, and separating the isoprene formed from the other4. A- process for producing isoprene,

which comprises passing the vapors of isoamylenetoxid of the formulaom-c cnon, AH

atmospheric pressure and separating the isopreneformed from the otherproducts.

5. The recess for producing isoprene whichco nsists inpassing the vaporsof iso-' amylene oxid of the formula over heated dehydrating catalyticsat temperaturcs from 400 600 G. in coma, at

1 over. heated aluminum-silicate, at less than pressures less than 00millimeters 0f mertnres from 400 to 600 C. in vacuo, at pres cury. suresless than 60 millimeters of mercury.

6. ,The process for producing isoprene In testimony whereof We alfix oursignawhich consists in passing the vapors of iso- 'tures in presence oftwo Witnesses.

5 amylene of the formula RICHARD BLAIR EARLE.

LUCAS PETRON KYRl'AKl DES. CH3C-CHCH3 CH3 W 1tnesses:

Jnssm R. Mon, 10 over heated alumlnum slllcate at tempera- M. ALICEHAGAR'IY.

